Pin tumbler lock



ec E?, H966 A. CHESLER 392%,893

PIN TUMBLER LOCK Filed April e, 1965 J4 J6z 1313 /A/ VEN 70@ @AWM/W @H552 E?? United States Patent O 3,293,893 PIN TUMBLER LOCK Abraham Chesler, 357 Midwood Road, Woodmere, N.Y. 11598 Filed Apr. 8, 1965, Ser. No. 446,610 7 Claims. (Cl. 70-385) This invention relates to pin tumbler lock construction and deals more particularly with masterkeying of pin tumbler lock cylinders.

In the old art of masterkeying, the master key for an entire series of locks is set up and the change pins of the tumblers of all of said locks are adjusted in length so as to align with the break line, thereby permitting the plug to rotate, opening the lock. The lengths of said pins, of course, conform to the various depths of the cuts in the master key. For the change keys of said series of locks, the depths of the cuts are made deeper than those of the master key, thereby necessitating the addition of master wafers to the tumblers that are of such length as to again produce the aligned or flush plugreleasing position at the break line.

Since each lock in said series may be opened not only by its change key, but also by the master key, the mas ter keys that had been provided for enabling locks to be opened and closed where they are being manufactured, where they are stocked for distribution, and in other places where such a series of locks is being installed, will also open these locks when they have been delivered to the ultimate user, as an individual item or in the doors lof autos, homes, etc.

The present invention has for an object to provide a pin tumbler lock that may be actuated by both its change key and by a master key, and in which the master key set-up of the tumblers may be disturbed so that only the change key will release the plug for lock actuation.

Another object of the invention is to provide a pin tumbler lock, as above characterized, in which at least one of the tumblers of a multi-tumbler lock, may be foreshortened, thereby disturbing or changing the position of its master key break line to prevent a master key operating the lock.

A further object of the invention is to provide a lock, as indicated, in which the change key break line of said tumbler, while also changed, is provided with a construction that establishes a new break line for this tumbler, and enables the change key and not the master key to release the plug for rotation.

My invention also has for its objects to provide means in a tumbler lock that are positive in operation, convenient in use, economical of manufacture, relatively simple, and of general superiority and serviceability.

The above objects are realized in a pin tumbler lock in which at least one of said tumblers may be operated on by a tool provide for the purpose to shorten the change pin of said tumbler to move the master key break line of said tumbler out of plug-releasing position while, at the same time, moving the initial change key break line out of its initial plug-releasing position and establishing a new change key break line that will release the plug. The tool, which need only be insertible into the key' slot of the plug, is provided with a recess into which a breakoff extension on the change pin enters. Upon extraction of the tool from the key slot, the break-oil eXtension is removed shortening the change pin and causing the above-mentioned disturbance of said tumbler, to prevent a master key from opening the lock. The tool may be provided with a tile-like edge which serves to remove rough break projections from the area from which the breakoll` extension had been removed.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description and which is based on the accompanying drawing. However, said drawing merely shows and the following description merely describes, one embodiment of the present invention which is given by way of illustration or example only.

In the drawing, like reference characters designate similar parts inthe several views.

FIG. l is a broken longitudinal sectional View of a pin tumbler lock according to the present invention in the initial condition thereof for release of the lock plug by both a change key and a master key, the View showing a change key in operative position in the lock.

FIG. 2 is a similar view showing said lock with a master key in operative position.

FIGS. 3 and 4 are views respectively similar to FIGS. 1 and 2 showing said lock converted so that its plug can be released only by the change key (FIG. 3) and not by the master key (FIG. 4).

FIG. 5 is a view similar to FIG. l, showing a tool in the lock preparatory to converting the lock.

FIG. 6 is an enlarged fragmentary longitudinal sectional view showing the tool in the process of being withdrawn after converting the lock to the condition of FIGS. 3 and 4.

The several views show the lock with a conventional cylinder body 10, and a plug 11 iitted in the cylinder bore 12.

For conventional masterkeying, each tumbler 13 of the several tumblers ordinarily fitted in the radial bores 14, comprises a change pin 15, a master wafer 16, and a driver pin 17, arranged one over the other, a spring 1S biasing the tumbler so the change pin 15 is in the path of a key inserted in a key slot 19 of the plug 11.

With no key in said slot 19, all of the tumblers 13, represented by the one that is illustrated, are projected by their springs 18 to the depths of their bores 14. In this position, a mid part of the driver pin 1'7 is aligned with the bore 12, the latter being the break line at which said driver pin and the wafer 16 part so the plug 11 can be turned by a key.

FIG. 1 shows a change key 20 with a notch 21 which so projects the tumbler 13 as to produce such a break line. FIG. 2 shows a master key 22 with a notch 23 which so projects the tumbler 13 as to produce a second break line between the change pin 15 and the master wafer 16, so said pin and wafer may part to permit turning of the plug.

The above describes conventional masterkeying which the present improvements contemplate changing so that the master key 23 will not produce a second break line along the length of the bore 12 and, therefore, will not open a lock which it was -originally intended to open.

To this end, at least one tumbler pin 24 is formed to comprise a special change pin 25 with an end break-oir extension 26 smaller in diameter than the change pin, a master wafer 27, an auxiliary wafer 28, and a driver pin 29 arranged one over the other, as before. A biasing springl 30 is provided, to project this tumbler. Such a tumbler, when the extension 26 is engaged with a notch 31 in the change key 20, produces a break line between the wafers 27 and 28, and when engaged with a notch 32 in the master key 22, produces a break line between the change pin 25 and the master wafer 27. Therefore, so long as the break-off extension 26 remains on the change pin 25, the tumbler 24 will be shifted by the'change key and by the master key to release the plug 11 for rotation.

In practice, the length of the extension 26 is less than the length of the master wafer 27 and is the same as length of the auxiliary wafer 28. Thus, as shown in FIGS. 3 and 4, when the extension 26 is broken off, the change pin 25 will engage the notch 31 of the change key 20 producing a break line between the wafer 28 and the driver pin 29, and the change pin 25 will engage the notch 32 of the master key 22 to cause the master wafer 27 to be so placed that a mid-part thereof is at the break line. Therefore, only the change key can open the lock.

By providing a narrow neck 36 on the extension 26 strong enough to remain intact while said extension rides over the slopes between the notches or recesses in the keys 20 and 22, and inserting into the plug a hard key-like tool 33 that has a notch 34 that is too small for the change pin 25 and into which the spring 30 will project the extension 26, as shown in FIG. 5, said extension may be broken away from the change pin, as shown in FIG. 6. Filelike serrations 35 on both sides of the notch 34 will le away rough parts on the end of the change pin, the tool being reciprocated in the key slot 19 to smoothen over the rounded end of the change pin. Of course, upon retraction of the tool, the broken extension and filings are extracted from the key slot. Any suitable manner of dislodging this debris may be used.

Instead of the extension 26 of the change pin 25 being integrally provided, the same may be attached by cement, such as epoxy cement, and broken away in the same way. The terms break-off and breakaway extensions are intended to include those that are cemented on.

It will be realized that the present pin tumbler lock is exemplary and, while it represents the best mode of carrying out the invention, as now contemplated, it is subject to modification. Therefore, I do not wish to restrict myself to the particular lock that is disclosed but desire to avail myself of all modifications that may fall within the scope of the appended claims.

Having thus described this invention, what is claimed and desired to be secured by Letters Patent is:

1. In a pin tumbler lock having a cylinder body and a plug having a key slot and rotationally fitted in said body, a plurality of radial bores extending from said key slot in the plug and into the cylinder body past a break line that coincides with the area of rotational interfit of the plug and cylinder of said body, a spring-biased pin tumbler in at least one of said bores comprising:

(a) a change pin provided with a break-off extension, the latter being provided on the end of the change pin that is directed toward the key slot,

(b) a master Wafer longer than said break-off extension engaged with the opposite end of the change pin, 'said engagement being at the break line when the extension is engaged in a notch in a master key,

(c) an auxiliary wafer of the same length as the extension engaged with the master wafer, said engagement being at the break line when the extension is engaged in a notch in a change key, and

(d) a driver pin engaged with said auxiliary pin, said engagement being in the portion of the bore that is in the cylinder body,

(e) said pin tumbler, upon removal of the extension on the change pin being biased into engagement with the notch in the change key with the engagement between the auxiliary wafer and driver pin at the break line, and biased into engagement with the notch in the master key with an intermediate part of the master wafer at the break line,

(f) the change key, thereby, setting said change pin both with and without the extension thereon in plugreleasing positions, and

(g) the master key, thereby, setting said change pin with the extension thereon in plug-releasing position, and with the extension removed in plug-locking position.

2. In a tumbler lock according to claim 1, the break-off connection comprising an end smaller in diameter than the diameter of the change pin.

3. In a tumbler lock according to claim 2, said extension being formed with a reduced breakaway neck.

4. In a pin tumbler lock having a cylinder body and a plug having a key slot and rotationally fitted in said body, a plurality of radial bores extending from said key slot in the plug and into the cylinder body past a break line that coincides with the area of rotational interfit of the plug and cylinder of said body, a spring-biased pin tumbler in at least one of said bores comprising:

(a) a change pin provided with a break-off extension, the latter being provided on the end of the change pin that is directed toward the key slot,

(b) and a hardened key-like tool insertable in the key slot of the plug and having a notch into which the extension is directed under the bias on the tumbler, said extension being disposed entirely within said key slot,

(c) said tool, upon retraction from the plug, removing the extension from the change pin.

5. In a pin tumbler lock having a cylinder body and a plug having a key slot and rotationally fitted in said body, a plurality of radial bores extending from said key slot in the plug and into the cylinder body past a break line that coincides with the area of rotational interfit of the plug and cylinder of said body, a spring-biased pin tumbler in at least one of said bores comprising:

(a) a charge pin provided with a break-off extension, the latter being provided on the end of the change pin that is directed toward the key slot,

(b) and a hardened key-like tool insertable in the key slot of the plug and having a notch into which the extension is directed under the bias on the tumbler, said extension being disposed entirely within said key slot,

(c) said tool, upon retraction from the plug, removing the extension from the change pin,

(d) said tool, on either side of said notch, being provided with serrations to smoothen the end of the change pin from which the extension was removed.

6. In a pin tumbler lock having a cylinder body and a plug having a key slot and rotationally fitted in said body, a plurality of radial bores extending from said key slot in the plug and into the cylinder body past a break line that coincides with the area of rotational interfit of the plug and cylinder of said body, a spring-biased pin tumbler in at least one of said bores comprising:

(a) a change pin provided with a break-off extension, the latter being provided on the end of the change pin that is directed toward the key slot,

(b) a reduced breakaway neck on said extension integrally joined to the change pin,

(c) said extension being smaller diametrally than the change pin,

(d) and a hardened key-like tool insertable in the key slot of the plug and having a notch into which the extension is directed under the bias on the tumbler, said extension being disposed entirely within said key slot,

(e) said tool, upon retraction from the plug, removing the extension from the change pin.

7. In a pin tumbler lock having a cylinder body and a plug having a key slot and rotationally fitted in said body, a plurality of radial bores extending from said key slot in the plug and into the cylinder body past a break line that coincides with the area of rotational interfit of the plug and cylinder of said body, a spring-biased pin tumbler in at least one of said bores comprising:

(a) a change pin provided With a break-olf extension, the latter being provided on the end of the change pin that is directed toward the key slot,

(b) a reduced breakaway neck on said extension integrally joined to the change pin,

(c) said extension being smaller diametrally than the change pin,

(d) and a hardened key-like tool insertable in the key slot of the plug and having a notch into which the extension is directed under the bias on the tumbler, said extension being disposed entirely within said key slot,

References Cited by the Examiner UNITED STATES PATENTS 3,070,987 1/1963 Baker et al 70--383 3,073,146 1/1963 Patriquin 70-383 3,190,093 6/1965 Schage 70-383 3,234,768 2/1966 Russell et al 70-383 EDWARD C. ALLEN, Primary Examiner. D P. TEITELBAUM, Assistant Examiner. 

4. IN A PIN TUMBLE LOCK HAVING A CYLINDR BODY AND A PLUG HAVING A KEY SLOT AND ROTATIONALLY FITTED IN SAID BODY, A PLURALITY OF RADIAL BORES EXTENDING FROM SAID KEY SLOT IN THE PLUG AND INTO THE CYLINDER BODY PAST A BREAK LINE THAT COINCIDES WITH THE AREA OF ROTATIONAL INTERFIT OF THE PLUG AND CYLINDR OF SAID BODY, A SPRING-BIASED PIN TUMBLER IN AT LEAST ONE OF SAID BORES COMPRISING: (A) A CHANGE PIN PROVIDED WITH A BREAK-OFF EXTENSION. THE LATTER BEING PROVIDED ON THE END OF THE CHANGE PIN THAT IS DIRECTED TOWARD THE KEY SLOT, (B) AND A HARDENED KEY-LIKE TOOL INSERTABLE IN THE KEY SLOT OF THE PLUG AND HAVING A NOTCH INTO WHICH THE EXTENSION IS DIRECTED UNDER THE BIAS ON THE TUMBLER, SAID EXTENSION BEING DISPOSED ENTIRELY WITHIN SAID KEY SLOT, (C) SAID TOOL, UPON RETRACTION FROM THE PLUG, REMOVING THE EXTENSION FROM THE CHANGE PIN. 